After Speaker Paul D. Ryan told reporters “Obamacare is the law of the land” last week following the defeat of the Republican bill to partially repeal and replace the 2010 health law, Republicans and President Donald Trump have begun to signal willingness to take another shot at health care legislation in the coming weeks. Roll Call’s White House correspondent John T. Bennett spells out what challenges may await the president on this issue, especially following his Thursday morning tweet decrying the House Freedom Caucus — the conservative group that largely opposed the defeated health care bill.